Conventionally, a vacuum forming apparatus for an article having a covering mounted on a substrate, such as an automobile interior component, includes a covering-side mold and a substrate-side mold to shape the covering and the substrate. The covering-side mold draws the covering with suction to shape the front surface of the covering in correspondence with the shape of the covering-side mold. The substrate-side mold draws the covering with suction through an air passage of the substrate such that the covering tightly contacts the surface of the substrate.
For example, an instrument panel, which is an automobile interior component, extends in the direction of the width of the vehicle and is mounted along the front windshield of the vehicle at the position facing the driver's seat and the front passenger seat. The instrument panel includes a covering, which is bonded to the surface of a portion of the substrate of the instrument panel. Specifically, the substrate and the covering are clamped between the substrate-side mold and the covering-side mold to be shaped as an integral body through a vacuum forming method.
As viewed in the direction of the vehicle width, the instrument panel is arranged in a zone including the vicinity of the glove compartment located on the side corresponding to the front passenger seat and the vicinity of the cockpit on the side corresponding to the driver's seat and curved in a manner projected from a front position of the vehicle toward the interior of the passenger compartment. The instrument panel is manufactured using vacuum forming apparatuses disclosed in, for example, Patent Documents 1 and 2.
A vacuum forming apparatus for an interior component described in Patent Document 1 will hereafter be described briefly with reference to FIGS. 10 to 12.
The vacuum forming apparatus has a first mold 52 (a covering-side vacuum suction mold) and a second mold 51 (a substrate-side vacuum suction mold), which are movable in the mold opening and closing direction VL (the vertical direction as viewed in FIG. 10). In advance, a substrate 10 is primarily shaped in a curved shape. With the first mold 52 and the second mold 51 maintained in an open state, the substrate 10 is attached to the second mold 51 such that the peak of the curved portion of the substrate 10 faces the first mold 52. A sheet-like covering 12 is arranged between the first mold 52 and the second mold 51, which are in the open state, and maintained horizontal by means of a clamp 55.
In forming operation, with the covering 12 held horizontal as shown in FIG. 10, the second mold 51 is raised to cause a portion of the covering 12 to cover the corresponding portion of the substrate 10. Subsequently, with reference to FIG. 11, the first mold 52 is lowered to cause the remaining portions of the covering 12 to cover the corresponding portions of the substrate 10. The first mold 52 and the second mold 51 are then closed. Then, the space between the first mold 52 and the second mold 51 is subjected to vacuum suction via the first mold 52 such that the front surface of the covering 12 is shaped in correspondence with the shape of the first mold 52. The second mold 51 then draws the covering 12 with suction through an air passage formed in the substrate 10 such that the covering 12 is bonded to the substrate 10. Afterwards, as illustrated in FIG. 12, the first mold 52 and the second mold 51 of the vacuum forming apparatus are separated from each other.
Generally, it is desired that the material forming the covering be small-sized to decrease costs. However, a small-sized covering may cause contact and interference between a holding member for holding the covering such as the clamp 55 and the molds when the covering is subjected to vacuum forming. This restricts the size reduction of the material forming the covering and the cost reduction of the covering.